Peptidyl arginine deiminase 2 (Padi2) is expressed in Sertoli cells in a specific manner and regulated by SOX9 during testicular development

Abstract

Peptidyl arginine deiminases (PADIs) are enzymes that change the charge of proteins through citrullination. We recently found Padi2 was expressed exclusively in fetal Sertoli cells. In this study, we analyzed the transcriptional regulation of Padi2 and the role of PADI2 in testicular development. We showed SOX9 positively regulated Padi2 transcription and FOXL2 antagonized it in TM3 cells, a model of Sertoli cells. The responsive region to SOX9 and FOXL2 was identified within the Padi2 sequence by reporter assay. In fetal testes from Sox9 knockout (AMH-Cre:Sox9flox/flox) mice, Padi2 expression was greatly reduced, indicating SOX9 regulates Padi2 in vivo. In vitro analysis using siRNA suggested PADI2 modified transcriptional regulation by SOX9. However, Padi2−/− XY mice were fertile and showed no apparent reproductive anomalies. Although, PADI2 is known as an epigenetic transcriptional regulator through H3 citrullination, no significant difference in H3 citrullination between wildtype and Padi2−/− XY gonads was observed. These results suggest Padi2 is a novel gene involved in testis development that is specifically expressed in Sertoli cells through the regulation by SOX9 and FOXL2 and PADI2 supports regulation of target genes by SOX9. Analysis of the Padi2−/− XY phenotype suggested a redundant factor compensated for PADI2 function in testicular development.

Diverse Regulation but Conserved Function: SOX9 in Vertebrate Sex Determination

“…The resulting Sertoli cells continually express SOX9 during testicular development. SOX9 acts as a part of a cascade, initiating a positive feedback loops for SOX9 expression, and upregulating expression of anti-Müllerian hormone (AMH), Desert Hedgehog (DHH), Peptidyl arginine deaminase 2 (PADI2), and Prostaglandin D2 synthase (PTGDS) [ 45 , 46 ]. Both SRY and SOX9 contain a sequence-specific DNA HMG-box capable of regulating transcription.…”

Delayed puberty, gonadotropin abnormalities and subfertility in male Padi2/Padi4 double knockout mice

“…Recent studies have already begun to document the presence of PAD2 in the testis. For example, Tsuji-Hosokawa et al showed that PAD2 appears to play an important role in testis development and is specifically expressed in fetal Sertoli cells, and that this expression is regulated by SOX9 a critical mediator of sex determination [ 15 ]. Another recent study used PCR, western blotting, and IHC to show that Padi2 is expressed in sperm during the first wave of spermatogenesis and appears to localize to the acrosomal region of the sperm head [ 16 ].…”

Fancd2os Reduces Testosterone Production by Inhibiting Steroidogenic Enzymes and Promoting Cellular Apoptosis in Murine Testicular Leydig Cells

“…1A , there are evolutionarily conserved variations in the Fancd2os protein among different genera, with 96.87% similarity in the amino acid sequence. To explore the expression patterns of Fancd2os, mature adult male mouse (6 months old) [ 21 ] tissues were collected, and Fancd2os expression was examined using RT-PCR and Western blots. These experiments showed that adult mouse testes exhibited a higher expression level of Fancd2os than other tissues ( Fig.…”

“…1B , C ). Moreover, testes from juvenile mice (1 month old), young mice (3 months old), middle-aged mice (12 months old), and aged mice (24 months old) [ 21 ] were analyzed to assess the temporal expression of Fancd2os. As illustrated in Fig.…”